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BULLETIN  OF 

ILLINOIS  COAL  MINING  INVESTIGATIONS 
COOPERATIVE  AGREEMENT 


Issued  bi-monthly 


VOL.  I 


January,  1915 


No.  6 


State  Geological  Survey 

Department  of  Mining  Engineering,  University  of  Illinois 

U.  S.  Bureau  of  Mines 


BULLETIN  9 


Coal  Mining  Practice 


IN 


District  III 


BY 
S.   O.  ANDROS 


Urbana 

University  of  Illinois 

1915 


[Entered  as  second-class  matter  Dec.  11,  1912,  at  the  Post  Office  at  Urbana,  111.,  under  tke 

Act  of  Aug.  24,  1912.] 


The  Forty-seventh  General  Assembly  of  the  State  of  Illinois, 
with  a  view  of  conserving  the  lives  of  the  mine  workers  and  the 
mineral  resources  of  the  State,  authorized  an  investigation  of  the 
coal  resources  and  mining  practices  of  Illinois  by  the  Depart- 
ment of  Mining  Engineering  of  the  University  of  Illinois  and  the 
State  Geological  Survey  in  co-operation  with  the  United  States 
Bureau  of  Mines.  A  co-operative  agreement  was  approved  by 
the  Secretary  of  the  Interior  and  by  representatives  of  the  State 
of  Illinois. 

The  direction  of  this  investigation  is  vested  in  the  Director 
of  the  United  States  Bureau  of  Mines,  the  Director  of  the  State 
Geological  Survey,  and  the  Head  of  the  Department  of  Mining 
Engineering,  University  of  Illinois,  who  jointly  determine  the 
methods  to  be  employed  in  the  conduct  of  the  work  and  exercise 
general  editorial  supervision  over  the  publication  of  the  results, 
but  each  party  to  the  agreement  directs  the  work  of  its  agents 
in  carrying  on  the  investigation  thus  mutually  agreed  on. 

The  reports  of  the  investigation  are  issued  in  the  form  of 
bulletins,  either  by  the  State  Geological  Survey,  the  Depart- 
ment of  Mining  Engineering,  University  of  Illinois,  or  the 
United  States  Bureau  of  Mines.  For  copies  of  the  bulletins 
issued  by  the  State  and  for  information  about  the  work,  address 
Coal  Mining  Investigations,  University  of  Illinois,  Urbana,  111. 
For  bulletins  issued  by  the  United  States  Bureau  of  Mines,  ad- 
dress Director,  United  States  Bureau  of  Mines,  Washington, 
D.  C. 


ILLINOIS  STATE  GEOLOGICAL  SURV^|T. 

33051  00006  3655 


ILLINOIS 
COAL  MINING  INVESTIGATIONS 

COOPERATIVE  AGREEMENT 


State  Geological  Survey 

Department  of  Mining  Engineering,  University  of  Illinois 

U.  S.  Bureau  of  Mines 


BULLETIN  9 


Coal  Mining  Practice 


IN 


District  III 


BY 
S.   O.   ANDROS 


Urbana 

University  of  Illinois 

1915 


CONTENTS 

Page 

Introduction   7 

Description    of    coal    beds 11 

Mining  practice 13 

Ventilation    19 

Blasting 21 

Timbering  .• 23 

Haulage  23 

Hoisting 26 

Preparation     of    coal 29- 


ILLUSTRATIONS 

Page 

Fig.   1.     Map   showing   area    (shaded)    of    District    III Frontispiece 

Fig.  2.     Method    of   drawing   pillars   13 

Fig.   3.     Method    of    slabbing    pillars 14 

Fig.  4.     Squared-up   end   of   pillar   in    slabbing IS 

Fig.   5.     Typical    gob    stopping 20 

Fig.   6.     Method    of    gaining    coal    without    using    powder 21 

Fig.   7.     Pit-car    hauled    by    dog 24 

Fig.   8.     Hopper  for  receiving  coal  at  bottom  of  shaft 27 

Fig.   9.      Surface    plant    at    local    mine 30 


TABLES 

No.  Page 

1.  General  data  by  counties  for  District  III  for  the  year  ended  June  30,   1912 8 

2.  Comparative  statistics  for  District  III  and  the  State  for  the  year  ended  June  30,  1912  9 

3.  Analyses  of  coals  in  District  III 11 

4.  Dimensions  of   workings   in   feet 16 

5.  Per  capita  production  of  coal 18 

6.  Pressure  developed  by  dust  of  face  samples  in  explosibility  apparatus 19 

7.  Data   relative   to   ventilation 20 

8.  Blasting   data    22 

9.  Data  relative  to  underground  haulage 25 

10.  Hoisting    data    27 

11.  Preparation  of  coal  for  market 29 


Fig.   1.     Map  showing  area   (shaded)   of  District  III 


COAL   MINING  PRACTICE  IN  DISTRICT  III 

By  S.    O.  ANDROS 


INTRODUCTION 

District  III  of  the  Illinois  Coal  Mining  Investigations,  as 
shown  in  fig.  1,  comprises  those  mines  in  Brown,  Calhoun,  Cass, 
Fulton,  Greene,  Hancock,  Henry,  Jersey,  Knox,  McDonough, 
Mercer,  Morgan,  Rock  Island,  Schuyler,  Scott,  and  Warren 
Counties  which  work  in  Rock  Island  coal  (bed  1)  and  Colches- 
ter coal  (bed  2)  of  the  Illinois  Geological  Survey  correlation. 
A  detailed  description  of  the  districts  into  which  the  State  has 
been  divided  and  the  method  of  collecting  the  information  upon 
which  this  bulletin  is  based  is  contained  in  Bulletin  1,  "A  Pre- 
liminary Report  on  Organization  and  Method." 

The  total  recorded  annual  production  of  this  district  for 
the  year  ended  June  30,  1912,  512,178  tons,  is  less  than  that  of 
one  large  mine  in  some  other  districts,  and  the  district  is  given 
a  separate  report  only  because  it  is  necessary  to  do  so  in  order 
to  have  a  complete  description  of  practice  in  the  State.  The 
recorded  figures  do  not  represent  quite  all  the  production  be- 
cause in  several  counties,  such  as  Cass,  Brown,  Calhoun,  Greene, 
Jersey,  and  Morgan,  there  is  a  little  coal  mined  at  outcrops  and 
on  various  farms  for  home  use.  The  amount  thus  mined  is 
negligible  by  comparison  with  the  reported  production.  Bed  1 
is  also  mined  at  Assumption  in  Christian  County,  100  miles  east 
of  District  III,  through  a  shaft  1004  feet  deep,  the  deepest  in 
Illinois.  Although  75,000  tons  arc  annually  produced  by  the 
isolated  Assumption  mine,  it  is  not  included  in  District  III  on 
account  of  its  geographical  separation. 

One  local  and  four  shipping  mines  were  examined  in  this 
district  in  which  there  are  123  local  and  5  shipping  mines. 

Comparative  statistics  have  been  compiled  for  the  year 
ended  June  30,  1012,  although  later  information  is  available, 
because  comparative  statistics  for  districts  previously  reported 
on  have  been  compiled  for  that  year  and  there  is  thus  made 
available  a  means  for  comparing  all  districts  in  the  State. 

7 


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INTRODUCTION 


0 


Table  1  gives  general  data  by  counties.  Table  2  gives  com- 
parative data  for  District  III  and  the  State  for  the  year  ended 
June  30,  1912. 

The  total  production  of  District  III  is  0.9  per  cent  of  the 
output  of  the  State.  The  amount  of  powder  used  is  out  of 
proportion  to  the  tonnage  produced,  1.9  per  cent  of  the  powder 
used  in  Illinois  being  used  in  this  district  although  a  consider- 
able quantity  of  the  coal  is  brought  down  by  wedge  and  sledge 

Table  2. — Comparative  statistics  for  District  III  and  the  State 
for  the  year  ended  June  SO,  1912* 


Total  production  

Average  daily  tonnage 

No.  tons  mined  by  machine 

Kegs  of  powder  used  in  blasting  coal 

Days  of  active  operation 

Number  of  days  work  performed  in  1912 

Total  employees  

No.  surface  employees  

No.  underground  employees  

No.    face   workers    (miners,    loaders,    and    ma- 
chine   men)b   

No.    underground   employees   per   each    surface 
employee  

No.  tons  mined  per  day  per  employee 

No.  tons  mined  per  day  per  surface  employee.... 

No.  tons  mined  per  day  per  underground  em- 
ployee     

No.  tons  mined  per  day  per  face  worker1' 

No.  fatal  accidents  

Per  cent  from  falling  rock  or  coal 

Per  cent  from  pit  cars  

Per  cent  from  explosives 

Per  cent  from  gas  explosions  

No.  deaths  per  tooo  employees 

No.  tons  mined  to  each  life  lost 

No.  non-fatal  accidents  

Per  cent  from  falling  rock  or  coal 

Per  cent  from  pit  cars 

Per  cent  from  use  of  explosives 

Per  cent  from  gas  explosions    

No.  injuries  per  1000  employees  

No.  tons  mined  to  each  man  injured 


512,178 

3,794 

9,5oo 

25,38] 

135 

(5 1. or  .5 

1,119 

■4-' 
977 

406 

6.9 

3-4 
26.7 

3-9 

7-0 

4 

50.0 

25-0 

0.0 

0.0 

3-6 

128,04  s 

6 

83.3 
0.0 
0.0 
0.0 
54 
85.363 


57,514,240 

359,464 

25,550,019 

1. 313.448 

160 

12,705,760 

79,4ii 

7,049 

72,362 

53,3i8 

10.3 

4-5 

50.9 

4-9 

6.7 
180 

54-4 

18.8 

7.2 

6.9 

2.3 

319,524 

800 

45-5 

26.3 

2.6 

2.8 

10.1 

71,893 


0.9 


1.9 


14 
2.0 

1-3 

0.8 


2.2 


0.7 


"Compiled  from  Thirty-first  Annual  Coal  Report  of  Illinois. 
bShipping  mines  only. 


10  COAL  MINING  INVESTIGATIONS 

without  powder.  Only  1.9  per  cent  of  the  output  is  undercut 
by  machines. 

The  two  mines  of  the  Coal  Valley  Mining  Company  are 
worthy  of  special  mention  inasmuch  as  they  recover  so  large  a 
percentage  of  the  coal  in  the  bed. 

Acknowledgments  should  be  made  to  the  superintendents 
and  mine  managers  who  gave  much  help  during  the  examination 
of  the  mines.  Especially  valuable  aid  was  rendered  by  Mr. 
Carl  Scholz,  President,  and  Mr.  Kobt.  E.  Lee,  General  Super- 
intendent, of  the  Coal  Valley  Mining  Company,  and  by  Mr.  Wm. 
D.  Godfrey,  President  of  the  Spoon  River  Coal  Company,  in 
supplying  information  and  in  revieAving  the  manuscript  of  this 
report. 


MINING  PRACTICE 


11 


DESCRIPTION  OF  COAL  BEDS 

The  cover  overlying  beds  1  and  2  in  District  III  is  thin. 
Bed  1  in  the  mines  examined  lies  at  depths  varying  from  40  to 
213  feet.  The  topography  of  the  surface  in  many  places  is 
rolling,  with  hills  about  150  feet  high  near  Matherville.  Bed  2 
lies  at  depths  of  7  to  100  feet  with  an  average  cover  of  55  feet. 

Bed  1  averages  4  feet  in  thickness  and  is  broken  in  places 
by  small  faults,  slips,  clay  veins,  and  rolls.  The  coal  has  weak 
vertical  cleavage,  dull  luster  and  banded  texture.  On  cleavage 
faces  thick  plates  of  calcite  and  iron  pyrites  are  deposited. 
Near  Ellisville  sulphur  bands  2  to  6  inches  thick  and  in  places 
50  feet  long  are  found  at  various  horizons.  A  poorly  developed 
parting  divides  the  bed  into  two  benches,  the  upper  of  which  is 
in  most  places  about  2  feet  thick. 

The  immediate  roof  in  the  northwestern  part  of  the  district 
is  a  hard  black  shale  that  is  easy  to  support.  In  the  southern 
part  of  the  district  in  places  a  bituminous  calcareous  shale,  2 
to  5  inches  thick,  lies  immediately  over  the  coal.  This  shale, 
called  clod,  is  hard  when  first  exposed  but  after  exposure  to  the 
air  becomes  soft  and  falls.  Throughout  the  district  the  cap 
rock  is  limestone.  In  limited  areas  where  the  shale  is  missing 
this  limestone  is  the  immediate  roof  over  the  coal.     Above  the 


Table  3. — Analyses  of  coals  in  District  11 V 


a; 
ft 

£ 
a 

in 
6 

Proximate  analysis  of  coal : 
1st,  "as  rec'd,"  with  total  moisture. 
2nd,  "Dry,"  or  moisture  free. 

3 

3 

-i-j 

6 

to 

'o 

c 

in 
< 

O 
O 

'5 

I 

II 

3 

15-58 
Dry 
17.40 
Dry 

39.17 
46.4O 
33-30 
40.32 

35.80 
42.41 
41.48 
50.23 

9-45 
II. 19 

7.82 
948 

4.69 

5.55 
2.03 
2.45 

10,673 
12,643 

10,811 

13,091 

2 

14,546 

14,663 

'Analyses  made  by  J.  M.  Lindgren  under  the  direction  of  Prof.  S.  W.  Parr. 


12  COAL  MINING  INVESTIGATIONS 

cap  rock  is  a  dense,  fine-grained  non-crystalline  limestone  lo- 
cally called  "blue  rock." 

Below  bed  1  in  places  there  is  an  irregular  band  of  hard 
bone,  3  to  6  inches  thick.  The  floor  proper  is  a  light  gray 
micaceous  fireclay  which  contains  plant  stems  and  roots.  This 
clay  heaves  badly  when  wet  and  in  places  SAvells  enough  to  fill 
the  entry.  In  parts  of  some  mines  a  carbonaceous  shale  lies 
between  the  fireclay  floor  and  the  coal  and  in  other  parts,  sand- 
stone.   These  casual  deposits  are  called  afalse  bottoms." 

Bed  2  varies  in  thickness  from  1  foot,  10  inches  to  4  feet 
and  averages  2%  feet.  The  bed  has  a  slight  east  dip  for  the 
district.  The  coal  has  a  weak  cleavage  and  dull  luster.  It  is 
finely  laminated  and  has  numerous  bands  of  mother  coal  and 
dirt,  none  of  which  is  continuous.  A  band  of  mother  coal  and 
iron  pyrites  persists  throughout  the  bed  at  a  distance  of  14 
inches  from  the  roof. 

The  immediate  roof  is  a  calcareous  shale  known  locally  as 
soapstone.  It  is  regular  and  smooth  and  contains  fossil  leaves 
in  places. 

The  floor  is  a  soft  gray  fireclay  which  contains  nodular 
concretions  of  iron  pyrites  called  sulphur  balls. 

Table  3  gives  analyses  of  the  coals  in  beds  1  and  2. 


MINING  PRACTICE 


13 


MINING  PRACTICE 

The  coal  in  this  district  lies  near  the  surface  but  nowhere 
is  the  overburden  stripped.  The  bed  is  reached  by  a  slope  at 
17  mines ;  by  a  drift  at  74 ;  and  by  a  shaft  at  37.  At  a  few  mines 
where  the  coal  is  brought  to  the  surface  through  vertical  shafts, 
a  slope  is  also  provided  for  a  manway  and  for  exhaust  of  the 
ventilating  current. 


Method   of  drawing  pillars 


The  mining  system  at  all  1ml  two  of  the  mines  is  the  sim- 
plest form  of  double-entry  room-and-pillar.  The  coal  is  gained 
during  the  first  working  with  a  waste  of  pillar  coal  amounting 
to  about  45  per  cent  of  the  bed.  At  the  two  exceptions  a  per- 
centage of  the  bed  large  for  Illinois  room-and-pillar  mines  is 
extracted.  At  these  mines  75  per  cent  of  the  pillar  coal  is 
recovered  on  the  retreat. 

A  main-entry  and  parallel  air-course,  each  (>  feet  high  and 
8  feet  wide,  are  driven  from  each  side  of  the  shaft  toward  the 
boundaries.  Prom  these  main  entries  pairs  of  cross  entries  are 
driven  every  500  feet  at  a  right  angle  to  the  main  entries.  On 
the  cross  entries,  after  leaving  a  barrier  pillar  of  50  feet,  rooms 
are  turned  on  45  foot  centers.     Room-necks  are  7  feet  long  and 


14 


COAL  MINING  INVESTIGATIONS 


8  feet  wide  and  are  widened  to  the  left  at  an  angle  of  about  45 
degrees  reaching  full  room- width  of  26  feet  at  a  distance  of  14 
feet  from  the  point  where  widening  is  begun.  In  the  first  room, 
number  1,  on  each  entry  the  room-pillar  cross  cuts  are  closed 
by  gob  stoppings  after  the  number  1  rooms  have  holed  through ; 
the  line  of  number  1  rooms  is  kept  open,  thus  providing  two 
additional  air  courses  inasmuch  as  cross  entries  are  turned  off 
both  sides  of  the  main  haluage  entry. 


Fig.    3.      Method    of   slabbing   pillars 


After  the  entry  has  been  driven  to  the  limit  and  the  rooms 
on  it  worked  out,  beginning  with  the  last  pillar  on  the  entry, 
room  pillars  are  drawn  until  the  pillar  between  rooms  3  and  4 
is  reached.  The  room  pillars  between  the  main  entry  and  room 
4  are  left  as  a  protection  to  the  main  entry  and  air  course. 

The  method  of  drawing  pillars  is  shoAvn  in  fig.  2.  When 
the  room  is  driven  up  full  length  a  12-foot  cut  is  made  at  the 
face  of  the  room  through  the  pillar  (Fig.  2  "a").  A  slab  5  feet 
wide  (Fig.  2  "a")  is  then  shot  off  the  side  of  the  pillar,  after 
which  a  slab  4  feet  wide  is  shot  off  the  end  (Fig.  2  "b"),  and 
the  pillar  end  is  squared  up  again  by  shooting  another  slab  4 
feet  wide  off  the  end  (Fig.  2  "c").  The  slabs  shown  in  fig.  2, 
"b"  and  "c",  are  usually  shot  off  with  one  8-foot  hole  and  a  pop 
shot  but  occasionally  a  pop  shot  is  unnecessary,  as  the  first  shot 


MIXING  PRACTICE 


15 


sometimes  breaks  off  the  entire  slab.  The  process  is  repeated 
beginning  again  as  in  fig.  2  "d".  Fig.  3  shows  the  coal  as  illus- 
trated in  the  diagram  fig.  2  "c".  Fig.  4  shows  the  squared-up 
end  of  the  pillar  as  illustrated  in  diagram  fig.  2  "d". 

The  hard  roof  is  easy  of  support  and  often  stands  before  a 
break  takes  place  while  25  to  200  feet  of  pillar  is  being  drawn. 
When  the  roof  weight  becomes  too  heavy  the  roof  breaks  at 
the  pillar  ends.  The  cracking  of  the  props  gives  ample  warning 
of  the  break  and  work  is  discontinued  until  the  roof  comes  down. 
The  interval  between  the  first  heavy  cracking  of  props  and  the 
roof  break  is  usually  not  more  than  12  hours. 


Fig.   4.      Squared-up  end   of  pillar  in   slabbing 


A  break  line  of  about  25  degrees  with  the  face  of  the  rooms 
is  roughly  maintained.  II  sometimes  happens  that  roof  falls 
prevent  the  men  from  gelling  into  the  squared-up  pillar  ends 
to  continue  drawing  as  described  above,  in  which  ease  a  12-foot 
cut  is  again  made  completely  through  the  pillar  as  was  done  at 
the  face  of  the  room  when  drawing  began  and  with  this  new 
pillar  end  the  procedure  continues  as  before.  Very  little  pillar 
coal  is  lost  from  lliis  cause.  Mr.  Carl  Scholz,  President,  Coal 
Valley  Mining  Company,  states  that  at  their  mine  No.  3  at 


16 


COAL  MINING  INVESTIGATIONS 


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MINING  PRACTICE  17 

Matlierville  the  loss  of  pillar  coal  does  not  exceed  four  per  cent. 

The  cost  of  producing  coal  is  much  less  on  pillars  than  on 
advance  work  in  rooms.  Room  coal  costs  an  average  of  $1.25 
per  ton  at  the  pit  mouth  at  the  No.  3  mine  of  the  Coal  Valley 
Mining  Company  and  pillar  coal,  $1,015.  This  difference  in  cost 
exists  because  track,  yardage,  bottom  digging,  and  driving 
through  rolls  and  slips  are  very  properly  charges  against  room 
coal  while  there  are  no  such  charges  against  pillar  coal.  When 
pillars  are  drawn,  therefore,  the  average  cost  per  ton  for  the 
total  production  is  materially  reduced.  At  this  mine  rooms 
are  worked  with  one  man  at  the  face  but  two  men  are  placed  at 
each  pillar  and  at  the  face  of  each  entry. 

With  the  extraction  of  such  a  large  percentage  of  the  bed 
surface  subsidence  should  be  expected.  The  topography  of  the 
surface  is  rolling  and  subsidence  is  usually  indicated  by  cracks 
in  hillsides.  The  largest  single  area  affected  was  reported  to 
be  one  acre  which,  it  is  stated,  subsided  from  6  to  12  inches. 

Table  4  gives  dimensions  of  workings  at  the  mines  exam- 
ined in  the  district. 

No  large  flows  of  water  are  found  in  any  mines  and  small 
steam  pumps  near  tin1  shaft  bottom  suffice  to  keep  the  mines 
dry. 

The  laborers  in  the  district  are  chiefly  Americans,  English 
and  Scotch.  There  are  some  Swedes  and  Slavs.  Physical  con- 
ditions in  the  mines  are  such  that  any  miner  can  earn  excellent 
wages.  Face  workers  in  shipping  mines  in  District  III  gain 
daily  on  the  average  one  and  one-third  tons  more  coal  than  do 
face  workers  in  the  rest  of  the  State,  the  ratio  being  7.0  to  6.3 
as  shown  in  Table  5.  The  district  contains  only  mines  of  small 
production  and  consequently  there  are  disproportionately  few 
underground  employees  to  each  surface  employee.  Therefore 
the  daily  production  per  employee  is  somewhat  lower  than  in  all 
other  districts  combined.  At  one  mine  the  number  of  "company 
men"  employed  underground  and  on  the  surface  equals  the 
total  number  of  face  workers. 

The  production  of  the  district  is  so  small  and  the  number 
of  employees  so  few  that  accident  statistics  are  of  little  value. 
During  the  year  ended  June  30,  1912,  there  were  four  fatal 
accidents  making  the  number  of  deaths  per  1000  employees  3.6 
as  compared  with  2.3  for  the  State  as  a  whole.  There  were 
128,045  tons  of  coal  produced  to  each  life  lost  as  compared 
with  319,524  tons  for  the  State. 


18 


COAL  MINING  INVESTIGATIONS 


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MINING  PRACTICE 


19 


VENTILATION 

The  thin  cover  overlying  the  coal  makes  good  ventilation 
of  mines  in  the  district  easy  to  obtain  because  the  sinking  of 
shallow  shafts  or  slopes  is  comparatively  inexpensive.  Several 
mines  are  provided  with  a  slope  or  shaft  for  ventilation  in 
addition  to  the  usual  air-shaft  prescribed  by  law,  thus  making 
overcasts  unnecessary.  Hence,  ventilation  presents  no  difficult 
problems  and  on  account  of  comparative  freedom  from  gas  the 
quantities  of  air  delivered  by  the  fans  are  small,  52,000  cubic 
feet  per  minute  being  the  largest  volume  recorded.  Fans  are 
usually  not  reversible  but  are  designed  for  blowing  perma- 
nently. 


Table  6. — Pressure  developed  by  dust  of  face  samples  in  cxplosi- 

bility  apparatus 


District 

No.  samples 

Pressure  in 

pounds  per 

square  inch  at 

2  i  <  >2  degrees  F. 

I  

II  

III  

IV  

V  

VI  

VII  

VIII  

ii 

5 

5 
1/ 

7 

16 
24 

6 

8.400 
5.880 
7.805 
7.700 
7-105 
5-950 
7-175 
8.925 

The  dust  on  the  ribs  is  comparatively  wet  in  most  mines 
and  no  serious  explosions  have  occurred.  Pace  samples  of  the 
coal  when  dried  and  reduced  to  200-mesli  size  are  very  explosi- 
ble  as  shown  in  Table  0  which  compares  average  explosibilities 
of  the  coals  of  each  district.  The  pure  coal  dust  of  bed  2  in 
this  district  develops  in  the  explosibility  apparatus  a  pressure 
of  7.00  pounds  per  square  inch  at  a  temperature  of  2192  degrees 
F.  The  dust  of  bed  1  develops  a  pressure  of  8.00  pounds.  The 
average  pressure  developed  by  all  samples  collected  in  District 
III  from  mines  in  beds  1  and  2  is  7.81  pounds  per  square  inch. 
Freedom  from  explosions  is  obtained  by  the  moisture  of  the 
dust  and  by  the  admixture  of  shale  dust  with  the  coal  dust  on 
the  ribs  of  entries.  The  shale  droppings  from  the  roof  are 
ground  up  by  the  car  wheels  and  the  feet  of  men  and  mules  and 
the  fine  dust  thus  made  is  thrown  into  suspension  in  the  air  by 


20 


COAL  MINING  INVESTIGATIONS 


the  passage  of  trips  and  settles  on  the  ribs.  The  swelling  of 
the  floor  in  several  mines  provides  a  further  supply  of  inert 
dust  as  the  floor  material  soon  becomes  ground  into  fine  dust. 


Fig.    5.      Typical   gob   stopping 

The  humidity  of  mine  air  in  the  district  is  normal.  At 
one  mine  two  hygrometers  were  installed;  one  in  the  intake 
and  one  in  the  return.  Readings  of  these  hygrometers  were 
taken  three  times  daily  during  a  period  of  one  year.  These 
readings  gave  for  the  year  an  average  relative  humidity  of  91.29 
per  cent  for  intake  air  and  95.10  per  cent  for  the  return  air. 
The  average  temperature  of  the  return  air  for  the  year  was 
68.07  degrees  F. 


Table  7. 

— Data  relative  to  ventilation 

a 

«4-l 

M-H 

r-      C-!     <D 

^    cA    CLf 

M-l 

(U  «+H 

0  c 

Deptl 

air-s' 

in  f 

Size  of 

in  cle 

in  f 

5^ 

Width 

fan  i 

feet 

17 

210 

6  by  I2a 

Paddle 

18 

4 

18 

69 

8  by  iob 

Robinson 

10 

4 

19 

/O 

8  by  12 

Paddle 

12 

3/2 

22 

60 

4  by  5 

Paddle 

6 

2/2 

24 

40 

6  by  8 

Paddle 

6 

4 

aAlso  has  third  shaft,  8  by  14  feet  for  escapement. 

bMine  also  has  slope  for  escapeway  and  auxiliary  air-return. 


MINING  PRACTICE 


21 


The  presence  of  pyrites  in  the  floor  causes  gob  fires  where 
any  fine  coal  is  left  in  the  gob.  Such  fires  are  numerous  and 
cost  from  $5  to  $150  to  extinguish.  Where  possible  they  are 
loaded  out  on  mine  cars.  Where  they  can  not  be  loaded  out 
they  are  shut  off  with  gob  seals. 

Gob  stoppings  are  general.  Fig.  5  shows  a  typical  stopping 
for  the  district.  Those  stoppings  appeared  to  be  comparatively 
efficient  in  one  or  two  mines  but  generally  are  leaky.  A  gob 
stopping  in  place  4  feet  thick  costs  8  cents  per  square  foot  of 
face.  The  total  ventilation  cost  at  one  efficiently  managed  mine 
is  3.9  cents  per  ton  of  coal  hoisted.  In  determining  ventilation 
cost  at  this  mine  wages  of  foreman,  assistant  foreman,  pumpers, 
trappers  and  water  bailers  are  apportioned  in  the  segregation 
of  items  and  vetilation  is  charged  with  its  proportionate 
amount. 

Table  7  gives  data  on  ventilation. 

ELASTIC J 

One  mine  uses  coal  cutting  machines  but  the  output  of 
undercut  coal  is  only  1.9  per  cent  of  the  total  production  of  the 
district,  The  average  production  per  keg  of  powder  is  20.2 
tons.  Black  powder  is  used  exclusively  and  is  purchased  in 
steel  kegs.  Sizes  F,  FF,  and  FFF  are  used  at  the  mines  exam- 
ined.    Shots  are  fired  by  fuse  in  every  mine. 

The  blasting  methods  in  the  small  mines  which  use  powder 
are  wasteful  of  explosive  and  produce  an  unnecessary  propor- 
tion of  slack.  Holes  12  feel  dee])  are  not  uncommon.  At  the 
mines  which  use  powder  the  diameter  of  holes  is  21  U  inches. 


Fig.   6.     Method  of  gaining  coal  without  using  powder 


22 


COAL  MINING  INVESTIGATIONS 


In  several  shallow  country  banks  with  irregular  outputs 
not  exceeding  50  tons  per  day  no  shooting  is  done  in  gaining 
the  coal.  The  coal  is  brought  down  by  wedge  and  sledge  as 
shown  in  fig.  6.  Vertical  cuts  about  18  inches  wide  and  two 
feet  deep  are  made  in  the  coal  at  15  foot  intervals  and  an 
undercut  about  three  inches  high  and  two  feet  deep  is  made 
along  the  face.  Steel  wedges  are  driven  between  roof  and  coal 
at  three-foot  intervals  and  the  coal  breaks  away  in  large  blocks. 
The  longwall  system  can  not  be  used  at  these  mines  because 
where  the  coal  is  removed  under  any  considerable  area  of  roof, 
caves  extend  to  the  surface  and  sand  and  water  pour  into  the 
mine.    For  the  same  reason  no  attempt  to  draw  pillars  is  made. 

At  the  No.  2  mine  of  the  Coal  Valley  Mining  Company  at 
Sherrard  shooting  in  rooms  is  done  off  the  solid  but  one-half  of 
the  face  is  kept  about  eight  feet  in  advance  of  the  other  half. 
The  small  amount  of  powder  required  per  ton  of  coal  to  gain 
the  rear  half  of  the  face  is  offset  by  the  amount  it  is  necessary 
to  use  to  bring  down  the  tight  coal  of  the  advanced  half. 

Table  8. — Blasting  data 


l-*0 

OS 

o 

u 

i-i 

-a 

Is 

<U    l-i 
O    <U 

— .  *0 

.So 

t/3 

—1.0 
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O 

Oh 

o 
<v 

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Ji 

***  y 

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3 

ij  o 
s  bo 
K.S 

3     CO 

■f  § 

CU   O 

-a 

M-H 

0  **> 

Powder  cc 
cents  per  t 
coal 

O 
4->      QJ 

bfi  <u 

J.S 

So 

^    en 

o.S 

17 

Solid 
shooting 

F.& 
F.F. 

1-39 

18 

973 

3  to  12 

6l 

75 

18 

Solid 
shooting 

F.F. 

i-39 

18 

973 

4  to    9 

IOO 

75 

19 

Solid_ 
shooting 

F.& 
F.F. 

1.56 

16 

10.92 

4  to  12 

125 

— 

22 

No 

80 

shootinga 

24 

Solid 
shooting 

F.F. 

1-39 

18 

973 

4  to  10 

38 

70 

aUse  sledge  and  wedge. 
bFigures  supplied  by  operators. 


At  the  smaller  mines  where  powder  is  used  it  is  carelessly 
handled  and  often  delivered  to  the  working  places  during  the 
day  while  the  men  are  in  the  mine.  The  large  charges  often 
used  are  responsible  for  frequent  blow-out  and  windy  shots 


MINING  PRACTICE  23 

which  amount  to  one  per  cent  of  all  shots  at  some  mines.  About 
two  per  cent  of  shots  misfire. 

Table  8  gives  blasting  data  for  the  mines  examined. 

TIMBERING 

Timbering  in  this  district  is  devoid  of  interesting  features. 
The  roof  is  very  strong  and  stands  without  support  in  moderate 
spans. 

In  nearly  all  small  mines  occasional  entry  sets  at  clay 
veins  are  the  only  timbers  used  except  at  the  mine  entrance. 

Split  room-props  are  usually  bought.  A  high  percentage 
of  white-oak  props  is  obtainable  in  this  district;  shipments 
containing  from  25  to  50  per  cent  of  white  oak.  The  length 
purchased  varies  from  3%  to  4%  feet.  The  life  of  props  aver- 
ages 18  months  on  the  return  air  ways. 

It  is  not  unusual  to  find  rooms  where  no  propping  at  all 
has  been  done  and  even  in  the  larger  mines  propping  is  not 
systematic.  The  roof  is  often  unsupported  for  a  distance  of  50 
to  75  feet  from  the  face.  A  more  frequent  inspection  of  the 
working  places  would  result  in  a  decrease  of  accidents  from 
fall  of  roof  and  coal. 

In  pillar  drawing  props  are  set  10  to  15  feet  from  the  face 
and  are  spaced  at  irregular  intervals.  Spragging  the  coal 
should  be  enforced  during  pillar-drawing  where  the  coal  is  un- 
dercut by  hand. 

At  all  of  the  mines  examined  shafts  and  slopes  are  timber 
lined.  No  steel  is  used  for  roof  support.  The  shaft  bottoms 
are  usually  lined  with  12  to  18-inch  framed  3-piece  sets  carrying 
2-inch  lagging.  The  legs  of  the  sets  are  usually  given  a  batter 
of  one  inch  for  eacli  vertical  foot  between  collar  and  rail. 

At  one  mine  with  a  daily  production  of  850  tons  the  total 
timbering  cost  including  labor  in  timbering  entries  is  1.1  cents 
per  ton  of  coal  hoisted.  An  average  cost  of  2.5  cents  per  ton 
is  estimated  for  the  district. 

HAULAGE 

In  the  thin  seams  of  District  III  entries  are  not  sufficiently 
high  for  animal  haulage  after  the  coal  has  been  removed.  The 
necessary  height  is  provided  at  each  mine  examined  by  lifting 
about  one  foot  of  the  fireclay  floor. 

The  outputs  of  the  largest  mines  in  the  district  are  so 


24 


COAL  MINING  INVESTIGATIONS 


small  that  haulage  at  high  speed  either  on  the  main  entries  or 
in  gathering  is  unnecessary.  Mechanical  haulage  is  used  in 
only  four  of  the  128  mines  in  the  district  and  mule  haulage  in 
7.  In  the  other  117  mines  cars  are  pushed  by  hand.  Where 
the  coal  is  pushed  by  hand  small  cars  are  used  weighing  empty 
from  225  to  250  pounds  and  holding  about  one-half  ton  of  coal. 
In  one  mine,  cars  for  many  years  were  hauled  to  the  bottom 
by  dogs  as  shown  in  fig.  7.  At  two  of  the  mines  examined  coal 
is  moved  from  the  partings  to  the  bottom  by  main-and-tail 
rope.  At  one  of  these  the  haul  is  1%  miles ;  at  the  other,  2000 
feet.  Second-motion  engines  located  near  the  bottom  of  the 
shaft  operate  winding  drums  three  feet  in  diameter.  The  inby 
bullwheel  is  4  feet  in  diameter  at  each  mine  and  both  main  and 


Fig.    7.      Pit-car   hauled   by   dog    (Photo   by   Mr.   James   Taylor) 


tail  ropes  are  %-inch  diameter.  At  one  of  these  two  mines, 
which  has  an  output  of  850  tons  daily,  there  are  250  cars 
underground.  Each  car  weighs  empty  1600  pounds  and  has 
a  capacity  of  1%  tons  when  topped  14  inches.  Twenty  loads 
are  hauled  out  in  each  trip.  At  the  other  mine,  which  produces 
500  tons  daily,  there  are  350  cars  underground  but  each  car 
weighs  empty  only  800  pounds  and  has  a  capacity  of  one  ton 
with  14  inches  of  topping.  Trips  average  56  cars.  Haulage 
costs  at  these  two  mines  approximate  7  cents  per  ton  of  coal 


MINING  PRACTICE 


25 


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:/) 

D 

U 

u 

£ 

g 

0 

0 

CO 

0 

too 

u 

C 

u 

0 

Ui 

^Uh 


26  COAL  MINING  INVESTIGATIONS 

hoisted.  This  amount  does  not  include  cost  of  steam  for  wind- 
ing engine  but  does  include  cost  of  gathering  with  mules. 
Gathering  alone  costs  4%  cents  per  ton.  The  company  oper- 
ating these  mines  raises  all  mule  feed  on  its  own  land  and  the 
feed  and  care  of  mules  average  $5  per  month  per  mule.  The 
company  pays  $135  each  for  mules  whose  working  life  averages 
eight  years.  At  the  mine  with  500  tons  output  there  are  14 
mules  for  gathering.  Each  mule  in  gathering  hauls  two  loaded 
cars  to  the  partings.  The  average  haul  is  1800  feet  and  each 
mule  pulls  an  average  of  38  loaded  trips  per  day.  The  average 
grade  in  favor  of  the  loads  is  2  per  cent,  The  road  bed  at  these 
mines  is  in  excellent  condition. 

Gasoline  locomotives  are  used  at  two  mines.  Their  ton- 
mileage  is  low  because  the  output  of  the  mines  is  small  and  the 
locomotives  are  never  worked  to  capacity.  Haulage  costs  were 
not  available  at  either  mine.  At  one  of  them  with  a  production 
of  850  tons  the  ton  mileage  of  the  locomotive  is  512.  At  this 
mine  the  haul  for  loads  from  partings  averages  1500  feet.  This 
locomotive  which  weighs  5  tons  uses  8  gallons  of  gasoline  per 
shift ;  one  gallon  for  each  106  tons  of  coal  hauled. 

At  the  other  mine  there  is  a  T-ton  gasoline  locomotive. 
Here  the  output  is  350  tons  daily.  This  locomotive  uses  12 
gallons  of  gasoline  per  shift;  one  gallon  for  each  29.2  tons 
hauled.  It  requires  2%  gallons  of  engine  oil  daily;  one  gallon 
for  each  140  tons  hauled.  This  locomotive  has  a  ton  mileage  of 
only  150.  Its  poor  performance  and  high  consumption  of  gaso- 
line and  lubricant  are  due  to  light  rails  and  neglect  of  the  road 
bed  which  is  in  poor  condition  having  high  grades  and  many 
sharp  curves. 

In  this  district  it  is  the  universal  custom  to  stable  mules 
and  ponies,  which  are  used  at  some  mines,  on  the  surface.  The 
-cost  of  a  pony  is  about  $150. 

Table  9  gives  haulage  data  for  the  mines  examined. 

HOISTING 

The  mines  of  this  district  are  shallow  and  their  production 
is  small.  Coal  is  brought  to  the  surface  by  steam  hoists  at  42 
mines;  it  is  brought  out  in  drifts  by  horses  or  hoisted  through 
shafts  by  liorse  whims  at  21 ;  and  by  hand  is  hoisted  by  windlass 
-or  pushed  to  the  drift  mouth  at  65.  There  has  been  no  necessity 
for  the  development  of  speed  in  hoisting  and  even  at  the  largest 


MINING   PRACTICE 


27 


mines  the  hoisting  engines  are  small.  At  every  mine  examined 
a  second  motion  engine  is  used.  The  Coal  Valley  Mining  Com- 
pany uses  skips  instead  of  cages  for  hoisting  coal.  For  hoisting 
men  and  lowering  timbers  and  other  supplies,  cages  are  used. 
The  hoisting  shafts  at  these  mines  have  four  compartments; 
two  for  skips  and  two  for  cages.  The  coal  is  dumped,  as  shown 
in  fig.  8,  into  a  hopper  built  beneath  the  floor  of  the  shaft  bot- 


Fig.   8.      Hopper  for  receiving  coal  at  bottom 


torn.  Each  of  the  two  compartments  of  the  hopper  has  a 
capacity  of  two  pit  cars.  The  hopper  discharges  automatically 
into  the  skips. 

Table  10. — Hoisting  data 


Hoisting  shaft 

<U            '■ 

Boilers 

tn 

>> 

bo 

~           ^ 

~  5  u 

*6 

'a 

<v 

0 

53      •- 

Oh' 

StCI 

(po 
re  in 

o 

c 

'""'  n-. 

,j3 

.5 

.S  ^ 

ffi 

rage 

sure 
squa 

c 

<u   C 

^-    OJ 

<u 

<U     C/i 

>    C 

~    fcO 

0 

N 

0 

0 

>    (U    u 

f£t 

<    °, 

m  2 

Q 

CO 

X 

H 

<-  aa 

17 

Soo 

Skip 

210 

T4  by  14^4 

14  by  24 

7 

500 

100 

18 

850 

Skip 

69 

10  by   14 

14  by  24 

3 

75" 

TIO 

19 

850 

No 

/O 

8  by  t6 

13  by  16 

3 

450 

100 

22 

30 

No 

60 

6  by  12 

1 

16 

70 

24 

350 

No 

40 

7  by  14 

9  by  12 

2 

300 

90 

28  COAL  MINING  INVESTIGATIONS 

At  no  mine  examined  is  caging  performed  automatically. 

Signalling  from  the  shaft  bottom  to  the  engine  room  at 
the  smaller  mines  is  done  by  pulling  a  wire  which  rings  a  bell 
in  the  engine  room.  The  pneumatic  signalling  device  is  not  in 
general  use.  The  hoisting  cable  is  either  iys  or  1%  inches 
in  diameter. 

Table  10  gives  hoisting  data. 


PREPARATION   OF  COAL 


29 


PREPARATION  OF  COAL 

At  nearly  all  the  small  mines  the  coal  is  sized  over  a  short 
gravity  bar-screen  and  only  two  sizes  are  made :  lump,  over  1% 
inches  and  screenings,  under  1%  inches.  The  per  cent  of  coal 
over  ±14  inches  in  size  produced  in  the  district  is  estimated  at 
70.  Several  mines  have  shaking  screens ;  usually  with  two  decks. 
One  mine  is  equipped  to  make  seven  sizes.  Theses  sizes  are 
rarely  all  made  in  one  run  and  usually  only  three  are  made  at 
any  one  time.    The  seven  sizes  are : 


Name 
Lump 


Egg 


No.  1 

No.  2 

Pea 

Slack 


nut 
nut 


Size 

Over  6  inches 

Through  6  inches;  over  3  inches 

or 
Through  6  inches;  over  2  inches 

or 
Through  G  inches;  over  ±14  inches. 
Through  3  inches;  over  1%  inches. 
Through  2  inches;  over  1%  inches. 
Through  1%  inches,  over  %-inch. 
Through  %-inch. 


Table  11. 

— Preparation  of  coal  for  market 

Sizing  screen 

.2 ^ 
0  ,^s 

u 

<+*  »- 

U 

0  f 

0 

a 

> 

c 

13  -■-> 

±^ 

/      D 

*J    V 

<u 

CD 

Of)    CD 

M      V 

^    13 

0  3  D 

C 

& 

u  &-C 

H 

CD 

£.s 

W    £ 

Oh    §.5 

17 

Shaking 

18 

12 

80 

75 

18 

Shaking 

12 

7 

85 

75 

19 

Shaking 

34 

6 

90 

22 

Gravity 

12 

6 

80 

24 

Shaking 

32 

5/2 

90 

70 

Inasmuch  as  the  market  for  much  of  the  coal  produced  is 
local,  sizes  are  made  to  meet  local  demand.  At  one  mine  6-inch 
lump  is  made  and  also  2-inch  lump.  There  is  a  local  demand 
at  this  mine  for  6-inch  mine  run.  The  demand  is  met  by  put- 
ting the  undersize  from  the  2-inch  lump  into  the  6-inch  lump. 


30 


COAL  MIXING   INVESTIGATIONS 


Table  11  gives  data  on  preparation  of  coal  for  market. 

There  are  no  steel  tipples  in  the  district.  Fig.  9  shows  the 
surface  plant  at  an  average  local  mine. 

The  power  plants  at  the  mines  of  the  Coal  Valley  Mining 
Company  are  remarkable  for  efficiency.     Coal  is  automatically 


Fig.   9.     Surfs 


plant  at   local  mine    (Photo  by   F.   H.   Kay) 


stoked  under  the  boilers  and  ashes  are  automatically  removed. 
At  these  mines  1.7  per  cent  of  the  total  production  is  burned 
at  the  plant. 

There  are  in  the  district  no  installations  of  air  compressors 
or  electric  generators  to  furnish  power  for  undercutting 
machines. 


PUBLICATIONS  OF  THE  ILLINOIS  COAL  MINING 
INVESTIGATIONS 


Bulletin  1. 
Bulletin  2. 
Bulletin  3. 
Bulletin  4. 


Bulletin  5. 
Bulletin  6. 

Bulletin  7. 
Bulletin  8. 

Bulletin  9. 


Bulletin  83, 


Preliminary  Report  on  Organization  and  Method 
of  Investigations,  1913. 

Coal  Mining  Practice  in  District  VIII  (Danville), 
by  S.  O.  Andros,  1914. 

A  Chemical  Study  of  Illinois  Coals,  by  Prof.  S.  W. 
Parr,  1914. 

Coal  Mining  Practice  in  District  VII  (Mines  in 
bed  6  in  Bond,  Clinton,  Christian,  Macoupin, 
Madison,  Marion,  Montgomery,  Moultrie,  Perry, 
Randolph,  St.  Clair,  Sangamon,  Shelby  and 
Washington  counties),  by  S.  O.  Andros,  1914. 

Coal  Mining  Practice  in  District  I  (Longwall), 
by  S.  O.  Andros,  1914. 

Coal  Mining  Practice  in  District  V  (Mines  in  bed 

5  in  Saline  and  Gallatin  counties),  by  S.  O. 
Andros,  1914. 

Coal  Mining  Practice  in  District  II  (Mines  in  bed 

2  in  Jackson  county),  by  S.  O.  Andros,  1914. 
Coal  Mining  Practice  in  District  VI  (Mines  in  bed 

6  in  Franklin,  Jackson,  Perry  and  Williamson 
counties),  by  S.  O.  Andros,  1914. 

Coal  Mining  Practice  in  District  III  (Mines  in 
beds  1  and  2  in  Brown,  Calhoun,  Cass,  Fulton, 
Greene,  Hancock,  Henry,  Jersey,  Knox,  Mc- 
Donough,  Mercer,  Morgan,  Rock  Island,  Schuy- 
ler, Scott,  and  Warren  Counties),  by  S.  O. 
Andros,  1915. 

United  States  Bureau  of  Mines,  The  Humidity  of 
Mine  Air,  by  R,  Y.  Williams,  1914.  (Copies  of 
this  bulletin  can  be  obtained  by  addressing  the 
Director,  Bureau  of  Mines,  Washington,  D.  C.) 


